Wont help improve the flame front or preignition. It is good for cold starts on a car with webers(no chokes). That I can tell you first hand. Also good for low end power and emmisions too.


Kurt Williams

The best thing is to take those two sparks and put them on opposite sides of the combustion chamber -- twin plugging.

OK, then you would consider MSD on a 2.7 with S or E cams etc. instead of the Bosch CD

Hey Kurt,
you know about the metro guys meet at McSorleys this Fri nite ?

Extended spark is a good thing since it has a greater probability of lighting the mix compared to one quick discharge, but once the mix is lit the additional spark is moot.

When Fuel control is Poor, MSD give the mixture a "2nd chance" at firing. If MSD were really helpful for modern cars, we would see it on production cars.

That said, I would replace a failed Bosh unit with an MSD, just for the cold start idle help and agreeing with CamB that it's NEW versus an old tired unit.

My 2.7 with Carbs and S cams (RS Spec) will use MSD.

Second strike sounds like the classic answer to a problem that doesn't exist.

I can tell you with authority that the MSD unit on my car (69 2.0E with S pistons) makes a massive difference at idle and low rev's (<3000 RPM). As was mentioned earlier, it does not provide the benefit of 2 spark plugs, but what it does do is ensure that each cylinder does fire as opposed to occasional mis-fires. I could hardly drive the car at 2000 RPM prior to the MSD without the engine bucking. Now I can pull top gear from below 2000 RPM to redline cleanly. Granted the later cars with the flatter combustion camber are most likely not as suseptiable to this problem, but the early 2.0 cars seem to respond well to MSD's.

At higher rev's (>3000 RPM) the motor runs great with or without the MSD. So what good would an extra spark do for me??? Nothing.

Thx for the post, John. Did the '69 come with the Bosch CD unit? And was it working fine before you used the MSD - or are you comapring to no CD box at all?

Yup, it had the CD box in it with the points replaced by a Crane optical trigger. Like I said, it ran fine once you were rolling at 3000 RPM and above, so I assume that the CD box was working since ignitions generally seem to fail at higher rev's first as the system's voltage starts to drop.